挑战习题
1/3单选题
难度:

1.设. 若对一切恒成立,则的取值范围是()
A
B
C
D [
提示1:
IOWPquimgeiuqeWHveaVsOWcqFs8aW1nIHdpZHRoPTc1IGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwL0QxLzk4L3JCQUNFMU5IeWRqRFFNdFRBQUFCaXlYVTJoYzc0MS5wbmciPuS4iueahOacgOWwj+WAvOWkp+S6juetieS6jjDlsLHlj6/ku6XkuobjgII=
提示2:
IOWPr+S7peaxguWvvOaVsO+8jOaxguWHuuWHveaVsOWcqFs8aW1nIHdpZHRoPTc1IGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwL0QxLzk4L3JCQUNFMU5IeWRqRFFNdFRBQUFCaXlYVTJoYzc0MS5wbmciPuS4iueahOacgOWwj+WAvOOAgg==
正确答案:QQ==
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